Warfarin could be an acceptable alternative for long-term treatment of cancer-associated thrombosis

A study presented at ASH 2015 found that switching to warfarin, after 6 months of anticoagulation with a low-molecular-weight heparin (LMWH), is not associated with an increase in the rate of recurrent VTE, when compared to continuing LMWH in patients with cancer associated thrombosis. Similarly, the rates of major bleeding, or total bleeding were similar for continued LMWH use and switching to warfarin. As such, warfarin could be an acceptable alternative for LMWH for patients with cancer-associated thrombosis, who can no longer tolerate LMWH therapy.

Thrombosis is a major problem in cancer patients and is considered to be the second cause of death in cancer patients, second only to the cancer. LMWH is considered to be the standard anticoagulation therapy for the treatment of cancer-associated thrombosis. The duration of treatment is recommended to maintain at least 3-6 months after the diagnosis. However, the data on continuing LMWH treatment beyond 6 months remains unclear. Most recommendations state that the anticoagulation therapy should be continued for as long as the risk for a recurrent thrombosis persists (patient under treatment, active cancer). However, prolonged LMWH use is costly and may also lead to a reduced quality of life.

In the study at hand, 1,502 cancer-associated thrombosis patients who completed treatment with a LMWH for 6 months were enrolled. The patients were divided into 2 groups: continued LMWH use, or switching to warfarin. The main study objectives included the incidence of recurrent venous thromboembolism (VTE), major bleeding and total bleeding. Of the 1,502 eligible patients who completed 6 months of anticoagulation therapy with a LMWH, 763 patients continued to receive a LMWH and 739 switched to warfarin. After a median follow-up of 11 months, there was no significant difference in terms of recurrent VTE between the 2 study groups (7.2% with LMWH vs. 6.0% with warfarin; HR [95%CI]: 0.70 [0.46-1.07]; p = 0.10). The cumulative incidence of major bleeding was also similar in both study arms at 2.6% in the LMWH group and 2.7% in patients receiving warfarin (HR [95%CI]: 1.05 [0.79-1.55]; p = 0.79). The cumulative incidence of total bleeding was 6.7% in the LMWH group and 7.0% in the warfarin group (HR [95%CI]: 0.92 [0.62-1.37], p = 0.70). As such, in patients with cancer-associated thrombosis who completed 6 months of anticoagulation therapy, switching to warfarin is not associated with an increased risk for a recurrent VTE, major bleeding or total bleeding when compared to continuing LMWH. The authors of this study concluded that warfarin is an acceptable alternative anticoagulant in cancer-associated thrombosis patients who do not tolerate long-term treatment with LMWH.


Chai-Adisaksopha C, Iorio A, Crowther M, et al. Switching to Warfarin after 6-Month Completion of Anticoagulant Treatment for Cancer-Associated Thrombosis. Presented at ASH 2015; Abstract #430.

Speaker Chatree Chai-Adisaksopha


Chatree Chai-Adisaksopha, Department of Medicine, MD,
McMaster University, Hamilton, Ontario, Canada


See: Keyslides


Back to Top